.game-container {
            background: white;
            border-radius: 20px;
            box-shadow: 0 20px 40px rgba(0,0,0,0.1);
            padding: 30px;
            max-width: 600px;
            width: 100%;
        }

        h1 {
            text-align: center;
            color: #333;
            margin-bottom: 10px;
            font-size: 2.5em;
            background: linear-gradient(45deg, #667eea, #764ba2);
            -webkit-background-clip: text;
            -webkit-text-fill-color: transparent;
            background-clip: text;
        }

        .subtitle {
            text-align: center;
            color: #666;
            margin-bottom: 20px;
            font-size: 1.1em;
        }

        .rules {
            background: #f8f9fa;
            border-radius: 10px;
            padding: 15px;
            margin-bottom: 20px;
            border-left: 4px solid #667eea;
        }

        .rules h3 {
            color: #333;
            margin-bottom: 10px;
        }

        .rules p {
            color: #555;
            line-height: 1.5;
            margin-bottom: 5px;
        }

        .game-info {
            display: flex;
            justify-content: center;
            align-items: center;
            margin-bottom: 20px;
            padding: 15px;
            border-radius: 10px;
        }

        .score {
            font-size: 1.2em;
            font-weight: bold;
            color: #667eea;
			display: none;
        }

        .controls {
            display: flex;
            gap: 10px;
            flex-wrap: wrap;
        }

        button {
            background: linear-gradient(45deg, #667eea, #764ba2);
            color: white;
            border: none;
            padding: 10px 20px;
            border-radius: 8px;
            cursor: pointer;
            font-weight: bold;
            transition: all 0.3s ease;
        }

        .tabs button:hover {
            transform: none;
            box-shadow: unset;
        }
		.nopad {
    /* float: left; */
    margin: 0 2rem 2rem 0;
}
		button:focus {
    
    outline-color: unset;
    outline-style: unset;
    outline-width: 0
}
		 button:hover {
            transform: translateY(-2px);
            box-shadow: 0 5px 15px rgba(102, 126, 234, 0.4);
        }
		.cell.hint {
			background: #ffeb3b !important;
			transform: scale(1.2);
			transition: transform 0.3s ease, background 0.3s ease;
}

        button:disabled {
            background: #ccc;
            cursor: not-allowed;
            transform: none;
            box-shadow: none;
        }

        .undo-btn {
            background: linear-gradient(45deg, #ff9800, #f57c00);
        }

        .undo-btn:hover {
            box-shadow: 0 5px 15px rgba(255, 152, 0, 0.4);
        }

        .grid-container {
            display: flex;
            justify-content: center;
            margin-bottom: 20px;
        }

        .kyodoku-grid {
            display: grid;
            grid-template-columns: repeat(6, 60px);
            grid-template-rows: repeat(6, 60px);
            gap: 2px;
            background: #333;
            padding: 10px;
            border-radius: 10px;
            box-shadow: 0 10px 25px rgba(0,0,0,0.15);
        }

        .cell {
            background: white;
            display: flex;
            align-items: center;
            justify-content: center;
            font-size: 1.4em;
            font-weight: bold;
            cursor: pointer;
            transition: all 0.3s ease;
            border-radius: 4px;
            position: relative;
            user-select: none;
        }

        .cell:hover {
            background: #e3f2fd;
            transform: scale(1.05);
        }

        .cell.fixed {
            background: linear-gradient(45deg, #4caf50, #45a049);
            color: white;
            cursor: default;
            position: relative;
        }

        .cell.fixed::after {
            content: '★';
            position: absolute;
            top: 2px;
            right: 2px;
            font-size: 0.8em;
            color: #ffeb3b;
        }

        .cell.hidden {
            background-image: linear-gradient(45deg, #ff9800 25%, transparent 25%), 
                              linear-gradient(-45deg, #ff9800 25%, transparent 25%), 
                              linear-gradient(45deg, transparent 75%, #ff9800 75%), 
                              linear-gradient(-45deg, transparent 75%, #ff9800 75%);
            background-size: 8px 8px;
            background-position: 0 0, 0 4px, 4px -4px, -4px 0px;
            color: transparent;
            position: relative;
        }

        .cell.hidden::before {
            position: absolute;
            color: #fff;
            font-size: 1.5em;
            font-weight: bold;
            text-shadow: 1px 1px 2px rgba(0,0,0,0.5);
        }

        .cell.validated {
            background: linear-gradient(45deg, #4caf50, #45a049);
            color: white;
            animation: validate 0.6s ease;
        }

        .cell.error {
            background: linear-gradient(45deg, #f44336, #d32f2f);
            color: white;
            animation: shake 0.5s ease;
        }
		button#checkBtn {
			display: none;
		}	
        
        .cell.selected {
            background: linear-gradient(45deg, #2196f3, #1976d2);
            color: white;
            transform: scale(1.1);
            box-shadow: 0 0 20px rgba(33, 150, 243, 0.5);
        }

        @keyframes validate {
            0% { transform: scale(1); }
            50% { transform: scale(1.2); }
            100% { transform: scale(1); }
        }

        @keyframes shake {
            0%, 20%, 40%, 60%, 80% { transform: translateX(0); }
            10%, 30%, 50%, 70% { transform: translateX(-5px); }
            90% { transform: translateX(5px); }
            100% { transform: translateX(0); }
        }

        .victory {
            text-align: center;
            margin-top: 20px;
            padding: 20px;
            background: linear-gradient(45deg, #4caf50, #45a049);
            color: white;
            border-radius: 10px;
            animation: celebration 1s ease;
        }

        @keyframes celebration {
            0% { transform: scale(0.8); opacity: 0; }
            50% { transform: scale(1.1); }
            100% { transform: scale(1); opacity: 1; }
        }

        .sums-display {
            margin-top: 20px;
            background: #f8f9fa;
            border-radius: 10px;
            padding: 15px;
        }

        .sums-display h4 {
            color: #333;
            margin-bottom: 10px;
            text-align: center;
        }

        .sums-grid {
            display: grid;
            grid-template-columns: 1fr 1fr;
            gap: 20px;
        }

        .sum-section {
            text-align: center;
        }

        .sum-values {
            display: flex;
            justify-content: center;
            gap: 10px;
            flex-wrap: wrap;
            margin-top: 5px;
        }

        .sum-value {
            background: #667eea;
            color: white;
            padding: 5px 10px;
            border-radius: 5px;
            font-weight: bold;
        }

        .sum-value.invalid {
            background: #f44336;
        }

        
       .tabs {
    display: flex;
    border-bottom: 1px solid #ccc;
    margin-bottom: 20px;
    justify-content: center;
    flex-wrap: wrap;
    gap: 2px;
}

.tab-btn {
    background: none;
    border: none;
    padding: 10px 16px;
    margin: 0;
    font-size: 1em;
    font-weight: bold;
    color: #555;
    cursor: pointer;
    border-radius: 0px;
    position: relative;
    top: 1px;
}

.tab-btn:hover {
    background: none;
}

.tab-btn.active {
    background: white;
    color: #000;
    border: 1px solid #ccc;
    border-bottom: 1px solid white;
    z-index: 1;
}



        .tab-content {
            display: none;
        }

        .tab-content.active {
            display: grid;
        }


        @media (max-width: 600px) {
            .kyodoku-grid {
                grid-template-columns: repeat(6, 45px);
                grid-template-rows: repeat(6, 45px);
            }
            
            .cell {
                font-size: 1.1em;
            }
            
            .game-container {
                padding: 20px;
            }

            .controls {
                justify-content: center;
            }
        }